require 'digest/sha1'
class User < ActiveRecord::Base
  # Authorization plugin
  acts_as_authorized_user
  acts_as_authorizable

  # Virtual attribute for the unencrypted password
  attr_accessor :password

  validates_presence_of     :login, :email, :name,       :if => :not_openid?
  validates_presence_of     :password,                   :if => :password_required?
  validates_presence_of     :password_confirmation,      :if => :password_required?
  validates_length_of       :password, :within => 4..40, :if => :password_required?
  validates_confirmation_of :password,                   :if => :password_required?
  validates_length_of       :login,    :within => 3..40, :if => :not_openid?
  validates_length_of       :email,    :within => 3..100,:if => :not_openid?
  validates_length_of       :name,     :within => 3..100,:if => :not_openid?
  validates_uniqueness_of   :login, :email, :case_sensitive => false
  before_save :encrypt_password
  
  # prevents a user from submitting a crafted form that bypasses activation
  # anything else you want your user to change should be added here.
  attr_accessible :name, :login, :email, :password, :password_confirmation

  # acts_as_state_machine :initial => :pending, :if => :not_openid?
  acts_as_state_machine :initial => :active
  state :passive
  state :pending, :enter => :make_activation_code
  state :active,  :enter => :do_activate
  state :suspended
  state :deleted, :enter => :do_delete

  event :register do
    transitions :from => :passive, :to => :pending, :guard => Proc.new {|u| !(u.crypted_password.blank? && u.password.blank?) }
  end
  
  event :activate do
    transitions :from => :pending, :to => :active 
  end
  
  event :suspend do
    transitions :from => [:passive, :pending, :active], :to => :suspended
  end
  
  event :delete do
    transitions :from => [:passive, :pending, :active, :suspended], :to => :deleted
  end

  event :unsuspend do
    transitions :from => :suspended, :to => :active,  :guard => Proc.new {|u| !u.activated_at.blank? }
    transitions :from => :suspended, :to => :pending, :guard => Proc.new {|u| !u.activation_code.blank? }
    transitions :from => :suspended, :to => :passive
  end

  # Authenticates a user by their login name and unencrypted password.  Returns the user or nil.
  def self.authenticate(login, password)
    u = find_in_state :first, :active, :conditions => {:login => login} # need to get the salt
    u && u.authenticated?(password) ? u : nil
  end

  # Encrypts some data with the salt.
  def self.encrypt(password, salt)
    Digest::SHA1.hexdigest("--#{salt}--#{password}--")
  end

  # Encrypts the password with the user salt
  def encrypt(password)
    self.class.encrypt(password, salt)
  end

  def authenticated?(password)
    crypted_password == encrypt(password)
  end

  def remember_token?
    remember_token_expires_at && Time.now.utc < remember_token_expires_at 
  end

  # These create and unset the fields required for remembering users between browser closes
  def remember_me
    remember_me_for 2.weeks
  end

  def remember_me_for(time)
    remember_me_until time.from_now.utc
  end

  def remember_me_until(time)
    self.remember_token_expires_at = time
    self.remember_token            = encrypt("#{email}--#{remember_token_expires_at}")
    save(false)
  end

  def forget_me
    self.remember_token_expires_at = nil
    self.remember_token            = nil
    save(false)
  end

  # Returns true if the user has just been activated.
  def recently_activated?
    @activated
  end

  def not_openid?
    identity_url.blank?
  end

  ########################################
  # Specialized Finders
  ########################################
  def find_audio_assets
    # See documentation of acts_as_authorizable plugin to understand this
 	  # Returns all AudioAssets for what user is Author
    self.is_asset_author_for_what
  end
  
  def find_programs
    # See documentation of acts_as_authorizable plugin to understand this
	# Returns all Programs for what user is Author
    self.is_author_for_what
  end
  
  # Returns all users that have the 'author' privilege
  def self.find_all_authors
    User.find_by_sql "SELECT DISTINCT u.* FROM users as u, roles_users as ru, roles as r 
		  WHERE r.name = '" + Role::Author + "' and r.id = ru.role_id and ru.user_id = u.id"
  end
  #######################################


  ########################################
  # Access Control Methods
  ########################################
  def is_updatable_by(user)
    return false if user.blank?
    self == user
  end
  
  def is_deletable_by(user)
    return false if user.blank?
    false
  end
  
  def self.can_update_users(user)
    return false if user.blank?
	user.has_role? Role::Editor or user.has_role? Role::Admin
  end
  
  def self.is_readable_by(user, object = nil)
    return false if user.blank?
    false
  end
  
  def self.is_creatable_by(user)
    return false if user.blank?
    user.has_role? Role::Editor
  end
  ########################################

  ########################################
  # Authorization Actions
  ########################################
  def self.enable_administration(id)
    @user = User.find id
    @user.has_role Role::Admin if @user
  end
  
  def self.disable_administration(id)
    @user = User.find id
    @user.has_no_role Role::Admin if @user
  end
  
  def self.enable_editorship(id)
    @user = User.find id
    @user.has_role Role::Editor if @user
  end
  
  def self.disable_editorship(id)
    @user = User.find id
    @user.has_no_role Role::Editor if @user
  end
  
  def self.enable_program_authorship(id, program)
    @user = User.find id
    @user.has_role Role::Author, program if @user && program
  end
  
  def self.disable_program_authorship(id, program)
    @user = User.find id
    @user.has_no_role Role::Author, program if @user && program
  end
  
  def self.enable_asset_authorship(id, asset)
    @user = User.find id
	@user.has_role Role::AssetAuthor, asset if @user && asset
  end
  
  def self.disable_asset_authorship(id, asset)
    @user = User.find id
	@user.has_no_role Role::AssetAuthor, asset if @user && asset
  end
  
  def self.enable_registered(id)
    @user = User.find id
    @user.has_role Role::Registered if @user
  end
  
  def disable_registered(id)
    @user = User.find id
    @user.has_no_role Role::Registered if @user
  end
  
  def is_author?
    self.has_role? Role::Author
  end
  
  def is_asset_author?
    self.has_role? Role::AssetAuthor
  end
  
  def is_editor?
    self.has_role? Role::Editor
  end
  
  def is_administrator?
    self.has_role? Role::Admin
  end
  ########################################

  protected
    # before filter 
    def encrypt_password
      return if password.blank?
      self.salt = Digest::SHA1.hexdigest("--#{Time.now.to_s}--#{login}--") if new_record?
      self.crypted_password = encrypt(password)
    end
      
    def password_required?
      not_openid? && (crypted_password.blank? or not password.blank?)
    end
    
    def make_activation_code
      self.deleted_at = nil
      self.activation_code = Digest::SHA1.hexdigest( Time.now.to_s.split(//).sort_by {rand}.join )
    end
    
    def do_delete
      self.deleted_at = Time.now.utc
    end

    def do_activate
      @activated = true
      self.activated_at = Time.now.utc
      self.deleted_at = self.activation_code = nil
    end

end
